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dc.contributor.authorGuzelturk, B.en_US
dc.contributor.authorErdem, O.en_US
dc.contributor.authorOlutas M.en_US
dc.contributor.authorKelestemur Y.en_US
dc.contributor.authorDemir, Hilmi Volkanen_US
dc.date.accessioned2015-07-28T12:01:52Z
dc.date.available2015-07-28T12:01:52Z
dc.date.issued2014en_US
dc.identifier.issn1936-0851
dc.identifier.urihttp://hdl.handle.net/11693/12549
dc.description.abstractColloidal semiconductor quantum wells, also commonly known as nanoplatelets (NPLs), have arisen among the most promising materials for light generation and harvesting applications. Recently, NPLs have been found to assemble in stacks. However, their emerging characteristics essential to these applications have not been previously controlled or understood. In this report, we systematically investigate and present excitonic properties of controlled column-like NPL assemblies. Here, by a controlled gradual process, we show that stacking in colloidal quantum wells substantially increases exciton transfer and trapping. As NPLs form into stacks, surprisingly we find an order of magnitude decrease in their photoluminescence quantum yield, while the transient fluorescence decay is considerably accelerated. These observations are corroborated by ultraefficient Forster resonance energy transfer (FRET) in the stacked NPLs, in which exciton migration is estimated to be in the ultralong range (>100 nm). Homo-FRET (i.e., FRET among the same emitters) is found to be ultraefficient, reaching levels as high as 99.9% at room temperature owing to the close-packed collinear orientation of the NPLs along with their large extinction coefficient and small Stokes shift, resulting in a large Forster radius of similar to 13.5 nm. Consequently, the strong and long-range homo-FRET boosts exciton trapping in nonemissive NPLs, acting as exciton sink centers, quenching photoluminescence from the stacked NPLs due to rapid nonradiative recombination of the trapped excitons. The rate-equation-based model, which considers the exciton transfer and the radiative and nonradiative recombination within the stacks, shows an excellent match with the experimental data. These results show the critical significance of stacking control in NPL solids, which exhibit completely different signatures of homo-FRET as compared to that in colloidal nanocrystals due to the absence of inhomogeneous broadening.en_US
dc.language.isoEnglishen_US
dc.source.titleACS nanoen_US
dc.relation.isversionofhttp://dx.doi.org/10.1021/nn5053734en_US
dc.subjectColloidal quantum wellsen_US
dc.subjectColloidal nanoplateletsen_US
dc.subjectNonradiative energy transferen_US
dc.subjectFörster resonance energy transferen_US
dc.subjectTime-resolved fluorescence spectroscopyen_US
dc.subjectExciton trappingen_US
dc.titleStacking in colloidal nanoplatelets: tuning excitonic propertiesen_US
dc.typeArticleen_US
dc.departmentDepartment of Physicsen_US
dc.departmentDepartment of Electrical and Electronics Engineeringen_US
dc.departmentInstitute of Materials Science and Nanotechnology (UNAM)en_US
dc.citation.spage12524en_US
dc.citation.epage12533en_US
dc.citation.volumeNumber8en_US
dc.citation.issueNumber12en_US
dc.identifier.doi10.1021/nn5053734en_US
dc.publisherAmerican Chemical Societyen_US
dc.contributor.bilkentauthorDemir, Hilmi Volkan
dc.identifier.eissn1936-086X


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